The traditional internal combustion engine relies on connecting rods for transmitting combustion power from a piston main body to a crankshaft of the engine, thereby converting the linear motion of the piston main body to rotational motion at the crankshaft. The connecting rod includes a crankshaft or big end surrounding the crankshaft, and a piston pin or small end that receives a piston or wrist pin. For ease of assembly to the crankshaft, the crankshaft end of the connecting rod may be sectioned into two portions. The first portion is part of the main body of the connecting rod, while the second portion is a separate cap that is secured to the first portion. The first portion may be secured to the cap by fasteners extending through bores in the cap to engage threaded bores in the first portion.
During operation of the engine, the fasteners securing the cap to the crankshaft end of the connecting rod sometimes become loose or separate from the bores. In particular, fastener separation depends on factors such as fastener pre-load, thread geometry and coating. Other factors may also include engine parameters such as revolutions per minute (RPM), resonance frequency, and transverse loads exerted on the connecting rod caused by crankpin and/or crank throw bending and crankpin to cylinder misalignment. Therefore, the connecting rod typically undergoes testing where the connecting rod is operated within an engine, e.g., simulating adverse operating conditions, in an effort to ensure that the fasteners remain secured within the bores during the normal operating life of the engine. During testing, the engine may be operated for at least several hundred hours to ensure that the fasteners remain secured to the first portion of the crankshaft end of the connecting rod. However, operating an engine for extended periods of time to perform this type of testing may become time-consuming and costly, as operating an engine for an extended period of time typically requires a substantial amount of fuel to power the engine. The complexity of engine assemblies may also lead to difficulties in repeating test results, as test engines may not accurately re-create identical operating conditions for the connecting rods. Moreover, many engine components or even the entire engine might need to be replaced after testing. Additionally, contaminants may be generated that could be minimized using a different mechanism.
Therefore, there exists a need to provide a device that simulates the loading conditions that may occur at the crankshaft end of a connecting rod during operation of a reciprocating engine.